1. Field of the Invention
The present invention concerns devices for moistening the flap of envelopes during automatic mail handling.
Devices of this kind are coupled to an inserter and in turn feed a device for closing envelopes whose flap has previously been moistened.
The present invention is more particularly concerned with a device for moistening envelope flaps in automatic mail handling machines which is able to moisten envelopes are to be dispensed closed or open.
2. Description of the prior art
A moistening device usually comprises a moistening member to which the gummed side of the flap of an envelope is applied as the envelope moves towards a closing device. The moistening member is supplied from a water reservoir. It is associated with a moistening deflector which forces the flap against the moistening member so that its gummed side is applied firmly to the moistening member.
In known moistening devices with a general organisation as described above the moistening deflector may be pivoted opposite the moistening member. A deflector of this kind is then movable between a rest position and a working position facing the moistening member. It provides for a particular mode of feeding envelopes with their body followed by the flap passing between the moistening member and the deflector in the rest position, so that the body of the envelope is not moistened. Independently of this particular mode of envelope feeding, it also enables the flap to pass freely between it and the moistening member, so that it is not moistened, or forces it against the moistening member to moisten it.
The operation of a moistening device of this kind with a selectively operable pivoted deflector is not entirely satisfactory. Although the deflector is held in the rest position, in which it does not operate on the flap, the natural fold line between the body of the envelope and the flap tends to cause the flap to bend towards the moistening member.
Because of this fold line and the flexibility of the flap, the gummed side of the flap, or at least part of it, may rub against the moistening member and so be moistened when moistening is not required.
An object of the invention is to provide a moistening device for selectively moistening envelope flaps which is relatively inexpensive and easy to implement and which does not have the previously mentioned disadvantages.